Many people argue that Android has put Linux into the hands of millions of users. While there is no doubting that Android has been a raging success, I would argue that Google has put Android into the hands of millions of people - not Linux. The following are my reasons for claiming such:
1.) Android's kernel is a Fork
Thats right, Android doesn't run on a mainline Linux kernel any longer. Their source code is maintained in a separate git repository because it was not accepted back into the main line kernel in it's current state and Google has not made any action towards improving the code so it can be accepted.
2.) Where is the brand name?
I did a post late last year titled "Keep the 'Linux' out of it Please", which asked whether using Linux in your brand name is deadly. Google seems to think so. Go do some digging on Android's homepage - I challenge you to find the word Linux on there anywhere. Even after digging through their development documents for some time I was unable to locate the word.
3.) Companies that don't support Linux support Android
Be it a game like Plants vs Zombies that Linux users are forced to run via Wine or a product such as Netflix streaming that does not run on Linux machines at all - there are lots of companies that refuse to support the penguin yet still produce Android applications. At the very extreme there is Adobe who has actually dropped support for Linux while continuing to write software for Android.
4.) All Java Applications
Android has piles of applications that are written for it. Unlike applications that are written for Linux though - they are not easily portable to other distributions. For instance applications written for WebOS are able to be run on the Maemo platform. Android applications however are all java based, meaning you need an emulator like Alien Dalvik to get them to run on other platforms.
5.) Microsoft doesn't make money off of Linux pre-installed Machines
There are plenty of vendors that sell systems pre-installed with Linux (such as BluSphere). Dedicated Linux users opt to purchase such systems (or system with no OS on it) in order to avoid the Microsoft Tax. When purchasing an Android handset there is no such avoidance. Up to 15$ per Android handset sold is going to Microsoft. Sure, this is the result of paten trolling - but I don't see anyone rising up to fight it.
6.) Where is the source code?
Yes there are closed source version of Linux. You know what is fairly unique to Android though? Claiming to be open source and then only releasing your source code to a select few hardware makers for a long while. Is it a solid business plan? Sure. Just don't claim to be free and open though and then pull something like this!
In my opinion at this point Android is just as much Linux based as OSX is BSD based. Now - don't get me wrong, I'm not saying Android is a bad operating system. In fact I'm glad it has taken away market share away from extremely closed operating systems such as iOS and Windows Mobile. I'm just saying lets stop calling it what it is not! Yes Android is Linux based it is not however Linux any longer.